Aspirin, Cooling and Exercise in Multiple Sclerosis

Research Questions The primary research questions guiding this project are: 1) Does oral ingestion of aspirin (650 mg in capsule form) 1 hour prior to exercise improve exercise capacity and reduce postural sway in the heat in a MS population? 2) Does spraying the skin with cold water during exercise improve exercise capacity and reduce postural sway in the heat in a MS population? Research hypotheses: The research hypotheses going into this study are: 1) Oral ingestion of aspirin (650 mg in capsule form) 1 hour prior to exercise will not improve exercise capacity or reduce postural sway in the heat in a MS population. 2) Spraying the skin with cold water during exercise will improve exercise capacity and reduce postural sway in the heat in a MS population. Exercise and balance protocol (assessing exercise capacity and postural sway) The exercise and balance protocol that will be used to test the participants exercise capacity and postural sway in the 3 familiarisation sessions and the 4 experimental trials (separated by at least 10 days for aspirin washout and delivered face-to-face by an Accredited Exercise Physiologist over a total time frame of approx. 2 months) is as follows: 1. 15-minute rest for baseline measures (experimental sessions only) and 15-minute postural sway testing on a low profile pressure-sensing mat 2. 20-minute pre-load cycling on an electronically braked semi-recumbent cycle ergometer at 50% pred. HRR 3. 20 minutes for rest and postural sway testing on a low profile pressure-sensing mat 4. 10-minute cycling time trial on an electronically braked semi-recumbent cycle ergometer 5. 20 minutes for postural sway testing on a low profile pressure-sensing mat and recovery Experimental trials The study will consist of four experimental trials which will take place in the climatic chamber with conditions set at 35ºC/40RH with participants completing the exercise and balance protocol (see details above) with: 1. Control - no intervention 2. Skin cooling using ~11mL of ~18 degree Celsius water sprayed onto the skin of the face, neck and arms every 5 minutes throughout the exercise protocol (COOL) 3. Oral ingestion of 650mg aspirin 1 hour prior to the exercise protocol (ASP) 4. Oral ingestion of one dose of 650mg non-active microcrystalline cellulose 1 hour prior to the exercise protocol (PLA)